I don't understand your diagram: pfSense will normally have a LAN and WAN interface. Which pfSense interface has IP address 10.0.0.1?

Your diagram suggests the pfSense interface connected to the modem has IP address 10.0.0.1 but that doesn't appear to be in the same IP subnet as the modem (or is it a modem-router?) because the diagram suggests that the IP address on the interface connected to pfSense is 192.168.1.1.
These two IP addresses need to be in the same IP subnet else the two boxes won't be able to communicate.

Please provide the IP address and network mask of all the interfaces in both boxes. The output of pfSense shell command```
/etc/rc.banner

You have a configuration error: your WAN interface has IP 2.219.x.166 assigned by DHCP but the gateway you have configured has IP address 192.168.1.1. The gateway is not on the same IP subnet as the pfSense WAN interface hence pfSense can't access the gateway.

Your edit(s) to your original post makes it even less informative.

Where is the DHCP server for the pfSense WAN interface? Perhaps it is providing inconsistent information. (Normally the DHCP server will provide an IP address for the interface and IP address of a gateway.)